equine dental diseases joan howard isu equine field services

Equine dental diseases

Joan HowardISU Equine Field Services

Why do horses need regular and thorough dental care?

To prevent serious health problemsTo make eating and performing more comfortable for the horse

Dental Anatomy

Eruption of teeth

Horses have long permanent teeth which continue to erupt during the horse’s life time.

Width of mandible and maxilla

Maxilla is widerthan mandibleOutside of uppercheek teeth andinside of lower teeth become sharp

Types of dental disease

Congenital abnormalitiesEruption abnormalitiesDental trauma Disorders of wearPeriodontal diseaseTooth infections

Congenital abnormalities

Underbite Overbite

Eruption abnormalities

Variations from the normal pattern in which teeth penetrate thegums.

Eruption abnormalities: supernumerary teeth (extra teeth)

Last molar the most commonly affected

cheek toothIf tooth is unopposed maycause problems

Eruption abnormalities

Displaced eruptions

Eruption Abnormalities

Dentigerous cyst Dental tissue is located at sites away

from the jaw often found in the temporal area with

a sinus tract leading to the base of the opposite ear

Eruption abnormalities

Unerupted wolf teeth wolf teeth lay parallel to the maxilla instead of eruptingthrough the gum If not removed may cause resentment ofbit

Eruption abnormalities

Retained caps If caps are not shed may impact

permanent tooth If removed too early may stop cause

abnormal development of cheek teeth

Eruption abnormalities Eruption cysts

Pressure of cap on unerupted permanent tooth can cause cyst formation in the mandible

may become infected

Eruption abnormalities

Retained deciduous (baby teeth) incisors May be mistaken as supernumerary

teeth Along with overcrowding, common in

miniature horses

Dental trauma

May result from dental procedures

Often due toDirect trauma

Dental trauma

Failure to treat appropriately may cause serious malocclusions

X-rays may be needed to evaluate the supporting bone

Disorders of wear

chewing surface irregularities

interfere with horse’s ability to chew food

most common form of equine dental disease

Disorders of wearSharp enamel points cheek teeth erupt, wear and develop

sharp enamel edges sharp edges can cause cheek and

tongue ulcerations

Sharp enamel points

pain may change chewing patterns and cause abnormalities of wear

Maxillary cheek teeth beforeand after floating

Disorders of wear

Hooks tooth overgrowths which develop as a

result of incomplete chewing surface contact

First cheek teeth and last cheek teeth commonly develop hooks which may cause oral pain and interfere with chewing

Rostral hooks ofsecond premolar

Disorders of wear

Wave mouth an undulating appearance of the

cheek teeth

Disorders of wearStep mouth A rectangular or triangular over

growth opposite a missing or shorter opposing tooth

Disorders of wear

Abnormalities of incisors More common on high grain diets Four different types

Periodontal disease

Progressive inflammation of the supporting structures of the toothPockets around gum-line of teeth may form

Complications of periodontal disease

Feed and debris may become impacted in the periodontal pockets and causeinfection and loss of thetooth

Tooth infections

May be caused by trauma, abnormal wear, or periodontal diseaseMay cause nasal discharge, sinus infection, draining from jaw, or loss of the toothTooth often needs to be removed

Infected maxillary cheek tooth

Infundibular necrosis

irregularities may be packed with food and lead to bacterial fermentation dissolution of surrounding cementum,

dentin and enamel infection of the pulp chamber splitting or cracking of the tooth

during mastication

Dental tumors

Odontogenic tumors Ameloblastoma Ameloblastic odontomas Complex odontoma Compound odontoma Cementoma

performing the dental

Equipment Examination Floating and correcting abnormalities

Equipment:Tranquilization

Safer and easier to do a thorough examination and treatment

Equipment

Dental halter: needs a noseband that allows the

horse to open its mouth wide enough to perform dental procedures

Equipment

Mouth speculums: Gag: a wedge is placed between the

upper and lower molar arcades. Can cause trauma to the teeth

Equipment

Full mouth speculum More cumbersome Need chemical restraint Mouth shouldn’t be left open for more

than 30 minutes. Allows better visual and digital

inspection of oral cavity

McAllen style speculum

Mcpherson type

Stubb’s speculum

Equipment

Head support

Equipment

Dose syringe

Light source

The examination

Look at the whole animalHistory of medical

of behavioral problemsCurrent on tetanus

vaccination? Consider the possibility

of other systemic problems

Examination of the headNote symmetry and conformation of head.Check for swelling of mandible or maxillaNote if nasal or ocular

dischargeOpen mouth and percuss

frontal and maxillary sinuses.Note lymph nodes

Oral examination

Rinse mouth with dose syringe 4 min after tranquilization of horse Note if food

packed in cheeks

Exam with full mouth speculum

Make sure that incisors are well placed on speculumKeep free hand on the horse’s nose or on the speculum

Examination with full mouth speculum

Observe oral soft tissue (palate, tongue, buccal mucosa).

Exam with full mouth speculum

Teeth: look at conformation, position and number. Occlusal surface

mid arcade long teethwave mouth cupped out teeth decayed

infundibula missing or

damaged crowns

Treatment of Dental Disease

Equipment Routine dental careTreatment of dental disorders

Hand floats

Rotary tools

Air driven equipment

Power float

Floating the cheek teeth with hand tools

purpose of floating is: to remove sharp enamel points from

the buccal edges of the maxillary cheek teeth

lingual aspect of the mandibular cheek teeth

to round the rostral surfaces of 06’s to Remove hooks, and level the arcades to restore the normal 10-15 degree angle to

occlusal surfaces

Maxillary cheek teeth

Easier to use two hands. Left hand is on the shaft of the float to control direction and amount of pressure placed on float.Keep blade at about a 45 degree angle to buccal side of tooth.

Floating mandibular cheek teeth

Remove enamel points from lingual edges of mandibular cheek teeth. Use a straight or offset float. Use two hands

Bit seatsthe bit may cause

discomfort when it presses soft tissue in the mouth against the rostral surfaces of 06’s

To make a bit seat, the rostral aspects of 06’s are rounded

Bit SeatBit Seat

Wolf tooth extraction

Local analgesics can be used Burgess elevator and root elevator loosen tooth

Extraction of Wolf ToothExtraction of Wolf Tooth

Treatment: disorders of wear

Over-growths are removed and strive to return to normal occlusionIn older horses over-growths are just taken out of occlusion

Treatment: disorders of wear

Incisor wear abnormalities Avoid removing more than 2mm of

incisors in one session

With fractures of mandible or avulsed incisorsStabilization may prevent malocclusions

Treatment: dental trauma

Pulp capping Debride and stop bleeding Calcium hydroxide or dental resin

used to restore tooth Keep out of occlusion 3 months If periapical sepsis remove tooth

Treatment: periodontal disease

Prevention by regular prophylactic careCorrect abnormal wear Periodontal pockets irrigatedPockets enlarged if possible to discourage food packingIf tooth is diseased, endodontic procedures or extraction may be necessary

Treatment: eruption abnormalities

Removing deciduous incisors Radiographs if position of

deciduous or permanent teeth is questionable

Elevate alveolar attachments Remove with forceps

Treatment: eruption abnormalities

Eruption cysts Remove deciduous cap if present

(may need radiograph to identify) Antibiotics if septic If apical damage may require

extraction

Treatment: eruption abnormalities

Unerupted wolf teeth May use radiographs to identify Place burgess over mucosa of rostral

aspect of tooth Tooth is elevated from attachments

Treatment: eruption abnormalities

Retained deciduous teeth Removing deciduous premolars

Identify crease between deciduous and permanent tooth

Use forceps, extractors or screw driver

Clamp base of capRock cap lingually

Treatment: infundibular necrosis

Extraction of tooth if severeRestoration of defect

Remove food from defect

Round bur used to prepare area

Dental adhesive then composit resin applied in 2mm layers

Treatment: Apical root infections

Conservative therapy with antibiotics

Better prognosis with mandibular teeth

Use broad spectrum antibioticsMay be more successful in younger

animals

Treatment: apical root infections

Sinus involvement trephination and irrigation Surgical endodontics (apicoectomy,

root end resection)More successful in mandibular

cheek teethRoot of tooth must be mature Mixed results among practitioners

Surgical endodontics

Treatment: apical root infections

Tooth extraction Lateral buccotomy Repulsion

Punch and mallet used to drive toothfrom its socket

Can damage supporting boneBreaks up tooth into small pieces